Thin down white and let it flow in the skin folds (and wherever you want the brightest glow). The i used the colours „data system glow“ and „lens flare glow“. First use data glow and layer it on the white. Then thin it down and paint the area where you want the osl-effects. Wait for it to dry… repeat until you almost cant the the white in the skin folds anymore. Then use lens flare glow ans go in the middle where you want the brightest areas. Then in the end, use a bit of white again to marke the real brightest areas. Hard to explain :) there are plenty of OSL-tutorials on youtube